Add Cash dependency, hopefully this will make the npm-run scripts windows compatible

Author: pygy

package.json

@@ -30,6 +30,7 @@
   },
   "homepage": "http://j2c.py.gy",
   "devDependencies": {
+    "cash": "^0.8.0",
     "codecov": "^1.0.1",
     "commonmark": "^0.24.0",
     "compose-regexp": "^0.1.8",